

    \filetitle{xsf}{Power spectrum and spectral density of model variables}{model/xsf}

	\paragraph{Syntax}

\begin{verbatim}
[S,D,List] = xsf(M,Freq,...)
[S,D,List,Freq] = xsf(M,NFreq,...)
\end{verbatim}

\paragraph{Input arguments}

\begin{itemize}
\item
  \texttt{M} {[} model {]} - Model object.
\item
  \texttt{Freq} {[} numeric {]} - Vector of frequencies at which the
  XSFs will be evaluated.
\item
  \texttt{NFreq} {[} numeric {]} - Total number of requested
  frequencies; the frequencies will be evenly spread between 0 and
  \texttt{pi}.
\end{itemize}

\paragraph{Output arguments}

\begin{itemize}
\item
  \texttt{S} {[} namedmat \textbar{} numeric {]} - Power spectrum
  matrices.
\item
  \texttt{D} {[} namedmat \textbar{} numeric {]} - Spectral density
  matrices.
\item
  \texttt{List} {[} cellstr {]} - List of variable in order of
  appearance in rows and columns of \texttt{S} and \texttt{D}.
\item
  \texttt{Freq} {[} numeric {]} - Vector of frequencies at which the
  XSFs has been evaluated.
\end{itemize}

\paragraph{Options}

\begin{itemize}
\item
  \texttt{\textquotesingle{}applyTo=\textquotesingle{}} {[} cellstr
  \textbar{} char \textbar{} \emph{\texttt{@all}} {]} - List of
  variables to which the option
  \texttt{\textquotesingle{}filter=\textquotesingle{}} will be applied;
  \texttt{@all} means all variables.
\item
  \texttt{\textquotesingle{}filter=\textquotesingle{}} {[} char
  \textbar{} \emph{empty} {]} - Linear filter that is applied to
  variables specified by `applyto'.
\item
  \texttt{\textquotesingle{}nFreq=\textquotesingle{}} {[} numeric
  \textbar{} \emph{\texttt{256}} {]} - Number of equally spaced
  frequencies over which the `filter' is numerically integrated.
\item
  \texttt{\textquotesingle{}matrixFmt=\textquotesingle{}} {[}
  \emph{\texttt{\textquotesingle{}namedmat\textquotesingle{}}}
  \textbar{} \texttt{\textquotesingle{}plain\textquotesingle{}} {]} -
  Return matrices \texttt{S} and \texttt{D} as either
  \href{namedmat/Contents}{\texttt{namedmat}} objects (i.e.~matrices
  with named rows and columns) or plain numeric arrays.
\item
  \texttt{\textquotesingle{}progress=\textquotesingle{}} {[}
  \texttt{true} \textbar{} \emph{\texttt{false}} {]} - Display progress
  bar on in the command window.
\item
  \texttt{\textquotesingle{}select=\textquotesingle{}} {[}
  \emph{\texttt{@all}} \textbar{} char \textbar{} cellstr {]} - Return
  XSF for selected variables only; \texttt{@all} means all variables.
\end{itemize}

\paragraph{Description}

\paragraph{Example}


